The food that farmers provide to livestock often includes prepared feeds. These prepared feeds may be as simple as milled grains, but they often comprise several ingredients including minute quantities of supplements such as vitamins and minerals. With some prepared feeds, the various ingredients are merely mixed together, but in other prepared feeds the ingredients are mixed and then formed into pellets, which typically involves the application of steam to the ingredients.
It is common in tracers for use in animal feeds to utilize inert chemical compounds which can be easily mixed with other ingredients and analysed for in samples, and also compounds of which the ingredients would have low levels, such that there would be low background levels. Another type of tracer utilizes colouring, either an ingredient which colours the entire feed product or small particles which are colour-coated and detectable by release of the colour with a solvent. These disclosed tracers are useful for determining the concentration of ingredients in a sample of feed, but they are of no use when it is necessary to distinguish between different batches of a particular prepared feed. Tracers of these types are limited in the scope of application because detection may be difficult when the tracer is diluted, and without a means of uniquely coding the tracer, consecutive batches of feed can not be differentiated.
In the feed industry, as standards of quality rise, and as public expectations of quality also rise, strict quality control management becomes more and more important, for example, the ability of the manufacturer to recall a specific batch if there is an error in mixing. The invention of a tracer which is readily detectable and coded, such that individual batches of feed products can be differentiated, will facilitate quality control procedures in the processing and distribution of such feed products.